| 摘要 |
PURPOSE:To improve the accuracy of positioning of an AC motor by previously measuring the frequency characteristics of a position detecting circuit and preparing beforehand a table frequency to phase. CONSTITUTION:The position signal Sa of a rectangular wave phase-modulated in response to the position of a resolver 25 is outputted displaced only by the angle of rotation thetaf to a reference signal Ref. A pulse signal Sb is outputted synchronizing with a clock signal phi1 on the rise of the rectangular position signal Sa. When the pulse signal Sb is outputted, a count signal Kb from a counter circuit 22 at that time is transmitted over a CPU 30. However, the pulse signal Sb does not represent the true value of the position of revolution of the resolver 25, and pulse number corresponding to a phase angle thetac corrected by a table at frequency to phase mounted into the CPU 30 is outputted as the true position of revolution of the resolver 25 regarding the actual position of revolution. |
